COST-EFFECTIVENESS ANALYSIS OF MIRIKIZUMAB VERSUS USTEKINUMAB IN ADVANCED THERAPY EXPERIENCED PATIENTS WITH MODERATELY TO SEVERELY ACTIVE ULCERATIVE COLITIS IN THE US

Abstract

Abstract BACKGROUND Mirikizumab, an interleukin (IL)-23p19 inhibitor, demonstrated efficacy compared to placebo in clinical trials in adult patients with moderately to severely active ulcerative colitis (UC). Mirikizumab is expected to receive approval from the United States (US) Food and Drug Administration in 2023. Ustekinumab, an IL12/23 antagonist, is the preferred option in advanced therapy (AT; biologics, novel targeted systemics) experienced patients. OBJECTIVES To evaluate the cost effectiveness of mirikizumab compared to ustekinumab in the US among patients diagnosed with moderately to severely active UC who have been previously treated with AT. METHODS A Markov model was developed in MS Excel, comprising an AT layer, a second line (2L) AT layer, a conventional treatment (CT) layer, and a surgery layer. Following initial induction (2-week cycle length), responders transition to maintenance, while non-responders transition to induction in 2L, consisting of a weighted mix of ATs used in clinical practice according to market shares, or CT. During the maintenance phase (12-week cycle length), the AT layers include remission and non-remission response health states; patients who lose response transition to the 2L, CT or surgery layer, comprising surgery and post-surgery health states. Death is possible from all health states, as per US 2020 national life tables. Probabilities for remission, non-remission response at the end of induction, and transition probabilities during maintenance were derived from a network meta-analysis and published literature, as were health state utilities. The analysis from a US payer's perspective over a lifetime horizon considered only direct medical costs in 2023 US dollars (USD). Costs and outcomes were discounted at 3%. Sensitivity analyses were performed; scenario analyses explored the impact of re-induction, dose escalation, and including societal costs. RESULTS Mirikizumab resulted in lower total costs (USD 1,232,582) and more quality-adjusted life-years (QALYs) (10.352) when compared to ustekinumab at standard doses (USD 1,279,620; 10.247 QALYs). Key drivers of cost savings (USD -47,038) and higher QALYs (0.105) for mirikizumab were assumptions on loss of response, the efficacy of mirikizumab at induction and the price of mirikizumab. The probability that mirikizumab is cost-effective at a willingness to pay threshold of USD 100,000 per QALY gained was 74.9%. Adopting an escalated dose for ustekinumab and re-induction for mirikizumab considerably increased savings. CONCLUSIONS The analyses provided insights into the cost-effectiveness of mirikizumab compared to ustekinumab in the US for patients with moderately to severely active UC previously treated with AT. Results demonstrated that adopting mirikizumab can be considered cost-effective compared to ustekinumab, contributing to decision-making in healthcare management.